The French Socialist party has distanced itself from Dominique Strauss-Kahn after he made comments published in the Guardian alleging that political enemies linked to Nicolas Sarkozy's rightwing party helped discredit him when he was accused of the attempted rape of a New York hotel housekeeper.

François Hollande, the Socialist candidate for the French presidency, who polls predict will win the runoff election against Sarkozy on 6 May, said on French TV that Strauss-Kahn – who once hoped to become the left's next president – "no longer has a role in political life" and had no business returning to it.

Hollande had already declared he would run against Strauss-Kahn in the Socialist primary race last year when Strauss-Kahn's political career was cut short by allegations he had assaulted and attempted to rape the New York hotel worker Nafissatou Diallo. Charges against Strauss-Kahn were eventually dropped, with prosecutors citing "substantial credibility issues" with the alleged victim. But Diallo's lawyers lodged a civil case against Strauss-Kahn over what they said was a "violent and sadistic attack", and a judge will rule on Tuesday on whether he can claim diplomatic immunity.

Strauss-Kahn, whose lawyers said the encounter with Diallo was consensual, is now considered a political pariah in France. Last month he was bailed and placed under formal judicial investigation for "aggravated procurement in an organised gang" – the legal term for pimping – in connection with his alleged involvement in a prostitution ring centred on the Hotel Carlton in Lille.

Socialists sought to draw a line under an embarrassing situation this weekend after several key party figures were invited to a birthday party in central Paris and swiftly left when they found Strauss-Kahn had also been invited.

The Socialist MP Julien Dray had invited Hollande's campaign director Pierre Moscovici, the communications director Manuel Valls and Hollande's former partner Ségolène Royal to a drinks party in a bar. But they reportedly left upon learning that Strauss-Kahn was to be among the guests.

Royal, who attended with her daughter, said she walked out as soon as she heard Strauss-Kahn was expected, and it was "out of the question" for her ever to meet him face to face, "in the name of women's rights and respect due to women".

Valls said Strauss-Kahn "has exited the campaign, he has no reason to come back into it". Jean-Marc Ayrault, tipped as a possible Socialist prime minister if Hollande wins, dismissed the Strauss-Kahn case as "a private affair subject to legal procedure".

Earlier on Saturday Sarkozy told a campaign rally in Clermont-Ferrand: "I say to Mr Strauss-Kahn, explain yourself with judicial authorities and spare the French people your comments."

Sarkozy's foreign minister, Alain Juppé, dismissed outright any suggestion of manipulation in the New York case, stressing the seriousness of the later prostitution investigation. "If it was a plot it would have been particularly clumsy. It would have been better to wait for the Carlton," Juppé said.

In an interview published by the Guardian, Strauss-Kahn told the American journalist and author Edward Jay Epstein that he believed the public undoing that followed his encounter with the New York hotel worker was the work of individuals linked to Sarkozy and his party. He did not say the incident with Diallo itself was a setup, but said the escalation of events into a criminal investigation that destroyed his chances of winning the presidency had been "shaped by those with a political agenda" and that "more was involved here than mere coincidence".

Epstein's ebook on his investigation of the scandal, Three Days in May, is published by Melville House on Monday.

On Sunday, Strauss-Kahn's entourage said he had not given an interview to the Guardian and it was a "montage" from Epstein's book. "This book written in indirect style does not contain any direct quotes from Strauss-Kahn," a source close to him told Agence France Presse.

In a statement, the newspaper said: "The Guardian stands by its story about comments made by Dominique Strauss-Kahn. The comments were made to investigative journalist Edward Jay Epstein during a two-hour interview with Mr Strauss-Kahn in Paris on 13 April. All comments attributed to Mr Strauss-Kahn in the interview and accompanying news story were made to Mr Epstein on 13 April. Naturally Mr Epstein included in his account of the interview background material from his book on the DSK affair, a short extract of which the Guardian published online. We note that Mr Strauss-Kahn does not dispute the substance of any of the comments reported by the Guardian.

"The timing of the Guardian's publication was determined only by the 30 April publication date of Mr Epstein's book."